Effects of naproxen on renal function in older patients with mild to moderate renal dysfunction

We have evaluated 45 elderly patients with both musculoskeletal problems and mild to moderate renal dysfunction. We treated these patients with a non-steroidal anti-inflammatory drug (NSAID) for 2 weeks. The serum creatinine, urinary creatinine clearance and blood pressure were monitored before and after therapy. In some patients serum levels of thromboxane B2 (TxB2) and the urinary prostaglandins E2 (PGE2) and I2 (prostacyclin) measured as 6-keto-PGF1 alpha were also monitored before and after therapy and correlated with the clinical measurements. This study has demonstrated that in the entire patient group, the trial drug was tolerated extremely well. There were no changes in the serum creatinine or in the urinary creatinine clearance after 2 weeks of therapy. There was also no change in the early morning diastolic blood pressure. In the 11 patients in whom the serum and urinary prostaglandins were measured, the serum thromboxane levels fell with therapy to a level of 1.5% of the initial value. The urinary levels of PGE2 also fell but not to the same degree. The urinary PGE2 levels fell to 28% of the baseline values. There was no significant change in the levels of urinary 6-keto-PGF1 alpha (prostacyclin). These observations suggest that prostacyclin may be the important prostaglandin in maintaining normal renal haemodynamics when patients are treated with NSAIDs.